Conventional water drainage from soil and soil consolidation are generally realized by vacuum preloading. To enhance the pumping and drainage effect, there are two treatment approaches. In the first approach, cathode tubes, anode tubes and a power supply are additionally provided in a vacuum preloading system to form a combined vacuum preloading and electro-osmosis drainage system. In the second approach, a boosting device is connected in pipelines of the vacuum preloading system, and the boosting device can provide boosting effect to the soil after preliminary pumping and drainage so that water around a boosting pipe is gathered to the surrounding of a drain pipe and water in the soil is drained more completely.